1. Field of the Invention
The present invention relates to a retention load plate, and more particularly to a retention load plate configured with a pair of moveably interlocked bars capable of moving toward and away from each other to adjust a span defined therebetween.
2. Description of the Prior Art
U.S. Pat. No. 5,722,848 issued to Lai on Mar. 3, 1998 discloses a typical connector socket, which is generally referred to as a ZIF (Zero Insertion Force) socket. In general, the socket includes a base with a plurality of contacts assembled therein, and a cover movably attached to the base. A lever with a cam mechanism is arranged between the base and the cover to drive the cover from a first position to a second position. When the lever is located in a vertical position, the cover is located at the first position, where a hole in the cover is completely in alignment with a corresponding passageway in the base. In this position, pins of a CPU can be inserted from the cover into the passageways without any engagement with the contact. When the CPU is properly seated on the cover, the lever is moved from the vertical position to a horizontal position, and simultaneously drives the cover from the first position to the second position. During this process, the pins of the CPU are then in contact with the contact within the base. The Lai '848 is specially used in a desk-top computer.
CPU socket used in a notebook is substantially similar to the one used in the desktop computer, and the key difference therebetween is that the lever used on the Lai '848 patent is replaced by a cam mechanism. When the cam mechanism is driven to rotate, the cover is driven to move along the base, therefore the pins of the CPU are then in contact with the contacts within the base, and since this is well known to the skilled in the art as well as laymen, no detailed description is given here for simplicity.
U.S. Pat. No. 7,001,197 issued to Shirai on Feb. 21, 2006 discloses another type of socket, which can be generally called LGA socket. The original pins type of chip occupies more space on the bottom surface of the CPU. In order to increase input/output speed, conductive pads are introduced to replace the pins so as to directly and electrically contact with contact terminals within the socket. No doubt, the speed is increased.
As clearly shown in Figures of Shirai '197, it features different configuration from to what Lai '848 discloses. The socket generally includes a metallic stiffener with a housing securely supported therein. Then a metallic clip is pivotally assembled to the stiffener. On the other hand, the clip is pivotally assembled to one side of the stiffener, and a lever has a cam which can lock the clip to a closed position when the clip is closed to the stiffener. By this arrangement, the CPU is seated on the housing before the clip is closed, and then the clip will tightly press the CPU toward the housing for ensuring proper electrical connection therebetween.
Shirai '197 can be applied to the desktop computer for it has more room for the operation of the lever, while it is almost impossible to apply Shirai '197 directly to the notebook in view of its small space.
Another factor to be considered is the configuration of the CPU. The CPU generally includes a substrate and a die mounted upon the substrate. Although the CPU is rigid, it is still vulnerable to be deformed when there is downward force applied thereon if the downward force is not evenly distributed. In Shirai '197 patent, the die is not pressed by the clip which has a window for it. The die is in direct contact with a heat sink.
Therefore, when installing an LGA socket into a notebook computer, the task of the even distribution of the downward force to both the die and the substrate is a difficult one, and therefore, serves as a motive for the present invention.
The configuration of heat sink is another factor to be considered. Typically, the heat sink device includes a bottom plate and a plurality of parallel heat sink fins disposed on the bottom plate. As the heat sink generally has a bulky configuration, it can be applied to a desktop computer which has a large space, but it is almost impossible to be applied to a notebook which has no sufficient space.
Therefore, there is a need to supply an improved electrical connector assembly with a heat dissipating device.